Viral infection remains an important health problem in both humans and in economically important livestock with adverse economic and social consequences.
One of the main approaches to protecting animals from viral disease is vaccination. Availability of sufficient quantities of virus, and the cost associated with virus production are limiting factors for the production of vaccines. There are current limitations with the production of influenza vaccine, and other vaccines, due to the reliance on an abundant supply of eggs. This is a particular issue when faced with producing enough vaccine to combat an emerging pandemic or to stockpile vaccine for pandemic preparedness. In addition, some virus are produced in cell culture systems which provide greater scalability options for pandemic preparedness. However, not all viruses replicate well in existing cell lines and thus are often not replicated at sufficient titres for cost effective vaccine production. Further, different strains of the same virus have different replication efficiencies in the same cell line which can limit the amount of vaccine produced and increase the cost of vaccine production in instance where viral replication is low.
Thus, there is a need to develop improved methods and cell populations for producing virus for vaccine production. In particular, there is a need to increase virus production in existing cell lines and to develop new cell lines for producing high virus yield and suitable for rapid scaling of size to meet the requirements for vaccine production for emerging pandemics and pandemic preparedness. It is against this background that the present inventors have developed a method and population of cells for replicating a virus in vitro.